Outboard Marine Drive

ABSTRACT

An outboard marine drive with an engine is described. The marine drive can include a drive housing with an upper drive housing and lower drive housing. The drive housing can be attached to a transom of a marine craft. An upper gear drive assembly can be located in the upper drive housing. A transmission can be provided with the upper gear drive assembly in the upper drive housing. In addition, a lower gear drive assembly can be located in the lower drive housing and coupled to the upper gear drive assembly. A propeller shaft may also be coupled to the lower gear drive assembly.

BACKGROUND

Outboard motors are typically built with a thin aluminum frame and other light weight alloys. Outboard motors are designed to run in open water with little or no expected impact to the outdrive assembly. This design restricts the boat operator from running the motor and boat along shorelines and in many waterways where impacts to the lower drive unit are likely and can damage the propeller, drive, and/or outdrive housing. Such impacts can come from rocks, logs, a waterway bottoms, or other similar obstacles. Sportsmen and others who desire to hunt, fish and travel in areas where obstacles reside in the water may avoid these areas as much as possible. Even then, what lies below the water's surface is usually a mystery, especially in muddy or murky waters.

The possibility of impact and damage to the lower end of an outboard motor is always present. As such, boaters must be constantly alert for sub-surface obstacles. When an impact to an outboard motor occurs, the boater is likely to face large motor repair bills. The inconvenience, safety hazard, threat of being stranded, and the financial losses of motor damage can be daunting for outboard motor owners.

SUMMARY

The technology provides an outboard marine drive with an engine. The outboard marine drive can include a drive housing with an upper drive housing and lower drive housing. The drive housing can be attached to a transom of a marine craft. An upper gear drive assembly can be located in the upper drive housing. A transmission can be provided with the upper gear drive assembly in the upper drive housing. In addition, a lower gear drive assembly can be located in the lower drive housing and coupled to the upper gear drive assembly. A propeller shaft may also be coupled to the lower gear drive assembly.

Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an outboard marine drive in accordance with an example of the present technology; and

FIG. 2 is a view of the example outboard marine drive of FIG. 1 with the drive housing removed.

FIG. 3 illustrates a view of an example outboard marine drive with the housing removed and a horizontally oriented transmission.

FIG. 4A is a side view of an outboard motor boat with a motor mounted thereto using a motor mount in accordance with an embodiment of the present technology;

FIG. 4B is a perspective view of a portion of the outboard motor boat of FIG. 4A.

FIG. 5 illustrates that the lower drive assembly and/or propeller shaft can be non-perpendicular with respect to the upper gear drive assembly input drive shaft.

DETAILED DESCRIPTION

Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

A transom mounted outboard motor technology is described here. More specifically, a heavy duty marine outboard is described with an upper shifting drive assembly.

FIG. 1 illustrates an outboard motor, indicated generally at 100, in accordance with the present technology. The outboard can include a drive housing with an upper drive housing 110 and lower drive housing 120, and the drive housing can be configured to be attached to a transom of a marine craft. A steering handle 130 can also be attached to the drive housing to steer the outboard marine motor. A shifter 132 can also be provided to actuate the shifting of the gears. The speed of the outboard marine motor can be controlled by a throttle control 140 on the end of the handle.

Having an outboard drive unit designed and built from thicker and stronger alloys that can sustain motor operations when the motor impacts objects at medium speeds can be an advantage to a boater. In addition to the use of strong alloys, the outboard motor can have certain structures that can allow the outboard motor to be used in taxing environments.

FIG. 2 illustrates a portion of an outboard marine drive with an engine. Specifically, FIG. 2 illustrates the drive train and propeller portions 200 of the outboard motor with the external drive housing(s) removed. As illustrated above, the outboard marine drive can have a drive housing with multiple housing pieces, and the upper and lower drive housing are removed in FIG. 2. The drive housing(s) can be configured to be attached to a transom of a marine craft using a clamping device 211, by bolts and/or other similar mechanism.

An upper gear drive assembly 210 can be located in the upper drive housing. A transmission 212 can also be located with or in the upper gear drive assembly in the upper drive housing. The transmission receives power from the engine and transmits power through the upper gear drive assembly. The transmission can also have a single speed or multiple speeds and the ability to change gear ratios in the upper gear drive assembly. For example, there can be multiple forward gears and multiple reverse gears in the transmission. A gear ratio selection can be provided in the transmission for forward or reverse motion of the marine craft.

In an example, the transmission can be a cone clutch that provides forward, neutral and reverse motion of the marine craft. Locating the transmission in the upper drive housing provides enough space for a transmission such as cone clutch, servo-cone clutch, multi-plate clutch, a hydraulic clutch, dog clutch, or another type of transmission. In existing outboards, transmission gearing is provided in the lower housing.

Existing marine motors have a fixed gearing that does not allow the operator to choose multiple gear ratio speeds when operating with varying boat loads. Also, when operating in obstacle ridden waterways, the benefit of gearing down to slow the forward motion of the boat is useful. A marine motor with multiple forward gears can be used in such gearing down circumstances. The ability to use multiple gear shifting for power boats of varying loads at different speeds provides flexibility for an outboard motor.

A power transfer gearing can be located between the upper gear drive assembly and the lower drive assembly with a first gear and first gearing size 232. The power transfer gearing can have a second gear 230 with a second gearing size similar to the first gearing size. The power transfer gearing can have a reduced size, as compared to existing outboard motors, due to the gears having a similar size. Since the transmission is in the upper portion of the drive housing, the power transfer gears can be smaller and similar in size. In addition, both of the gears can be strong due to their similar size and strength. A power transfer gearing is generally as strong as the smallest gear in the transfer system. So, the use of two gears of similar size can increase the strength of the power transfer gearing and avoids the use of a large gear in combination with a small gear. In one example, the gearing ratio between the upper gear drive assembly and the lower drive assembly is near a 1.20 gearing ratio as needed to match the engine size with the propeller. In another example, the lower drive housing can have gears with a reduced size due to a near 1-to-1 gearing ratio of the power transfer gearing. When there is no gear ratio change or a small gear ratio change, then the similar forces on the gears means that the gears are less likely to fail. Useful ranges of gearing in the described technology can range between a 1.1:1 to a 1.7:1 gearing ratio.

Previous outboard motors of vertical design provide changes to gear ratio in the lower drive assembly. Since the gear ratio relies on one larger gear and one smaller gear, the strength of the gear set is determined by the smaller of the two gears. In contrast, the present technology provides an outboard with the ability to run at a near one to one gear ratio in the lower drive assembly and this can allow the system to utilize a large and strong gear set while having improved external fluid drag efficiency. If a large gear ratio is used in the lower drive housing as in existing outboards, then this increases the fluid drag of the lower drive housing and increases the cross sectional area of the lower drive housing that can hit obstacles in the water. In contrast, the small gear ratio provides lower drag and a smaller cross-sectional area that is more likely to avoid obstacles in the water.

A lower gear drive 214 assembly can be located in the lower drive housing and be coupled to the upper gear drive assembly. A propeller shaft 216 and propeller 218 can also be coupled to the lower gear drive assembly. The propeller shaft can be an extended length shaft and can be more than 12 inches in length. The propeller may be located above the bottom of the marine craft.

A rudder fin 150 (FIG. 1) and cavitation plate 222 (FIG. 2) can be located on the lower drive housing of the outboard marine motor. A portion of the lower drive housing may extend below the bottom of the marine craft.

Referring again to FIG. 2, a flex coupler 224 (or impact dampener) may be configured to transfer power between the engine and the transmission. The impact dampener can be made of rubber or similar components that are able to absorb the shock of an impact from the transmission in order to preserve the transmission components from serious damage. Users of outboard motors value the ability to absorb medium to heavy impacts from underwater obstacles such as logs, stumps, heavy vegetation and other obstacles in the waterway.

FIG. 3 illustrates a view of an example outboard marine drive with the housing removed and a horizontally oriented transmission. The horizontally oriented transmission 310 is located in the upper drive housing and can be controlled by a shifter as described above.

Reference will now be made to FIGS. 4A-4B. FIG. 4B is a side view of an outboard motor boat 610 with a motor 605 mounted thereto using a motor mount. The motor includes a handle 615 described above, which can be used for steering and adjusting a trim or vertical positioning of the motor in the water. FIG. 4B is a perspective view of a portion of the outboard motor boat of FIG. 4A.

FIG. 5 illustrates that the lower drive assembly and/or propeller shaft can be non-perpendicular 500 to the upper gear drive assembly input drive shaft. In other words, the lower drive assembly or propeller shaft can form an obtuse angle with the upper gear drive assembly. The lower drive assembly or propeller shaft may also be located at a right angle with respect to the upper gear drive assembly as illustrated previously.

It is to be understood that the above-referenced arrangements are only illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention. While the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth herein. 

1. An outboard transom mounted marine drive with an engine, comprising: a drive housing having an upper drive housing and lower drive housing, the drive housing configured to be attached to a transom of a marine craft; an upper gear drive assembly located in the upper drive housing; a transmission with the upper gear drive assembly in the upper drive housing; a lower gear drive assembly located in the lower drive housing and coupled to the upper gear drive assembly; and a propeller shaft coupled to the lower gear drive assembly.
 2. The outboard marine motor as in claim 1, wherein the transmission has multiple speeds.
 3. The outboard marine motor as in claim 1, wherein the transmission receives power from the engine and transmits power to the lower gear drive assembly.
 4. The outboard marine motor as in claim 1, wherein the transmission includes a gear ratio selection for forward or reverse motion of the marine craft.
 5. The outboard marine motor as in claim 1, further comprising multiple forward gears in the transmission.
 6. The outboard marine motor as in claim 1, further comprising multiple reverse gears in the transmission.
 7. The outboard marine motor as in claim 1, wherein the transmission is a cone clutch.
 8. The outboard marine motor as in claim 7, wherein the cone clutch provides forward, neutral and reverse motion of the marine craft.
 9. The outboard marine motor as in claim 1, further comprising a propeller attached to the propeller shaft.
 10. The outboard marine motor as in claim 1, further comprising a steering handle attached to the drive housing to steer the outboard marine motor.
 11. The outboard marine motor as in claim 1, further comprising a throttle control to control the speed of the outboard marine motor.
 12. The outboard marine motor as in claim 1, further comprising a rudder fin on the lower drive housing of the outboard marine motor.
 13. The outboard marine motor as in claim 1, further comprising a cavitation plate fin on the lower drive housing of the outboard marine motor.
 14. The outboard marine motor as in claim 1, wherein the lower drive housing partially extends below the bottom of the marine craft.
 15. The outboard marine motor as in claim 1, further comprising a flex coupler configured to transfer power between the engine and the transmission.
 16. An outboard marine motor with an engine, comprising: a drive housing with an upper drive housing and lower drive housing, the drive housing configured to be attached to a transom of a marine craft; a upper gear drive assembly located in the upper drive housing; a transmission with the upper gear drive assembly in the upper drive housing; a lower gear drive assembly located in the lower drive housing and coupled to the upper gear drive assembly; a power transfer gearing in the lower gear drive assembly with a first gear having a first gear size and the lower drive assembly that has a second gear having a second gear size similar to the first gear size; and a propeller shaft coupled to the lower gear drive assembly.
 17. The outboard marine motor of claim 16, further comprising a lower drive housing that has a reduced size due to a near 1-to-1 gearing ratio of the power transfer gearing.
 18. The outboard marine motor of claim 16, wherein the gearing ratio between the upper gear drive assembly and the lower drive assembly is near 1.20.
 19. An outboard marine motor with an engine, comprising: a drive housing with an upper drive housing and lower drive housing, the drive housing configured to be attached to a transom of a marine craft; a upper gear drive assembly located in the upper drive housing; a gear reduction with the upper gear drive assembly in the upper drive housing; a lower gear drive assembly located in the lower drive housing and coupled to the upper gear drive assembly; a propeller shaft with an extended length greater than 12 inches that is coupled to the lower gear drive assembly; and a propeller attached to the propeller shaft. 